direct train from Venice to Merano?

No way there is a direct train. The best you can hope for is 2 train changes, at Verona Porta Nova and Bolzano.

Rome2Rio is pretty useless in my humble opinion. Use https://www.trenitalia.com/en.html. Start with Venezia S. Lucia and ending in Merano and you will get all the options. Use a date prior to June 12, as there is a schedule revision on that date and all the trains will not show up.

There is one single connection solution with an EC train from Venice to Bolzano and change to a train to Merano.

The train schedule past June 11 has not been updated
If your dates are past then you won’t see complete offerings yet

Have you checked Trenitalia site?
I see trains from Venice to Verona to Bolzano then to Merano
Fast trains to Verona and to Bolzano then regional
2 changes
About 4.5 hours

Also an EC train later in day- 1 change in Bolzano

Rome2rio is a fun tool but it can’t be relied on for complete and accurate info
Always go to the actual train site

Be careful booking Senior tickets on Trenitalia. Under the Terms and Conditions, the offer is limited to holders of the CartaFreccia.

https://www.trenitalia.com/en/html/trenitalia/Info_Tariffe_en_LeFrecce.html#SENIOR

But no worries; that route is also served by regional trains which are much less expensive than the fast Frecce trains, even though they have no special rate for seniors. And the segment between Verona and Bolzano is also served by the Eurocity trains on then render Pass route, which often will offer a discounted price for advance booking. I see those are still available for early June.

thanks everyone....I do have the Trenitalia app which I discovered was very very useful last year when I travelled! and I have the CartaFreccia so my senior discount gets applied automatically when there is one....I'll rely on that more than the Rome2Rome! again, thanks for all....Sandy